1. Field of the Invention
The invention relates to a window construction particularly adapted to resist conditions encountered during extreme storms. The window construction is used in an exterior window for a commercial or residential building, or a sliding glass door as typically leads between an interior room and a back porch or patio. The window construction functions as an integral part of the external protection for the building envelope, whether used as a window or sliding glass door, and includes high impact panes mounted in a structure of extruded frame parts in a manner that resists damage from pressure cycling and debris impact.
2. Prior Art
Exterior windows and/or sliding glass doors mounted in the walls of a commercial or residential buildings are intended to provide a weather-tight barrier against wind and rain. A window or sliding glass door also permits a view, and preferably has the capability of being opened during favorable conditions. It is possible to make a window or sliding glass door into a substantial barrier; however its viewing aspects and opening capabilities may suffer, and the expense of the window or door typically is increased. On the other hand, if the window or sliding glass door does not form a sufficient barrier, it may be damaged under extreme storm conditions.
Extreme storm conditions characterized by strong winds and rain, airborne debris and/or hail, occur yearly in various locales. Such conditions may occur in hurricanes or near tornadoes, or even in particularly strong thunderstorms. For example, in South Florida and along the Gulf Coast, hurricanes occur yearly or oftener.
In a strong storm, an exterior window or sliding glass door might be subject to winds of 75 mph (120 kph) or greater. Wind loading can be sustained, e.g., continuing for the greater part of a minute, or can occur in gusts and ripples. Both sustained and intermittent wind loading can cause structures to oscillate, and to withstand such loading, structures require both static strength and resilience.
Gale force winds load windows and/or sliding glass doors structurally and drive rain against the window or door and its seals. Moreover, such winds can carry debris. Smaller particles such as sand and gravel can damage window panes. In a strong storm, large missiles become airborne, such as pieces of roofing, loose lawn furniture and even structural parts of damaged buildings. A 9 foot (2.7 m) nominal 2.times.4 timber stud (5 cm.times.10 cm), weighing between 9 and 9.5 lbs (4.1 and 4.3 kgms) flung at a window at a speed of 34 mph (55 kph) or greater, for example, is a formidable missile. However wind borne debris of this type is not unusual in a hurricane.
Conventional windows and/or sliding glass doors for commercial and residential buildings generally have not been designed to withstand and/or resist such extreme weather. When subjected to high winds and debris, windows or sliding glass doors have failed or broken apart, allowing the weather and debris to invade the building envelope, and potentially leading to further structural damage due to a breach of structural integrity.
Experience has taught that hurricanes result in great losses, not only in property but in lives. What is needed is an improved window construction utilized in windows and sliding glass doors alike that better resists such extreme weather and/or storms. However, improved strength and debris resistance should be achieved without adversely affecting aesthetic aspects such as sufficient view and opening capability, and without unduly increasing costs.